Anxiety is known to affect the cognitive process of the mind. Explanations on the effects of anxiety on these processes have been refined through increasingly more detailed cognitive theories. The theories began as generalized views of anxiety being a distraction as could be seen in the concept of cognitive bias (Calvo and Eysenck, 1998). Research has provided an explanation that anxiety affected the functions of the central executive in the processing efficacy theory. Attentional control theory refined processing efficacy theory's explanation of anxiety. Attentional control theory pinpointed specific functions affected by anxiety. The theory shows that anxiety which is not related to the individual's present goal can impair shifting and inhibition functions in cognitive processing, but research into attentional control theory has shown that is related to the current goal anxiety causes an increase in processing efficacy (Causer, Holmes, Smith, and Williams, 2011). Understanding the different impacts of anxiety and how it relates to the individual and the goal at hand can serve to improve efficiency in functioning, learning, and responses of an individual. Further research concerning the refinement of current theories is discussed.